Kosher foods

The Torah permits eating only those land animals that chew their cud and have cloven hooves.[1][2] Four animals, the hare, hyrax, camel, and pig, are specifically identified as being forbidden because they possess only one of the above characteristics: the hare, hyrax and camel are hindgut fermenters and chew their cud but do not have cloven hooves, while the pig has a cloven hoof but does not chew its cud.[3]

The Torah lists winged creatures that may not be consumed, mainly birds of prey, fish-eating water-birds, and bats. Certain domesticated fowl can be eaten, such as chicken, geese, quail, dove, and turkey.

The Torah permits fish residing in "the waters" (seas and rivers) only having both fins and scales.[4][5] However, monkfish is not considered kosher, and other seafood considered non-kosher includes shellfish like clams, oysters, crabs and shrimps. There is also a risk of products like seaweed and kelp being contaminated by microscopic, non-kosher crustaceans.[6]

The Torah forbids two types of sherets (creeping things):

• Earth crawlers, e.g. mouse, lizard[7]
• Flying creeping things,[8][9] with four exceptions: Two types of locust, the beetle/cricket, and the grasshopper.[10]

In addition to meat, products of forbidden species and from unhealthy animals were banned by the Talmudic writers.[11] This included eggs (including fish roe)[12][13][14] and milk,[15] as well as derived products such as cheese and jelly,[15] but did not include materials merely "manufactured" or "gathered" by animals, such as honey (although, in the case of honey from animals other than bees, there was a difference of opinion among the ancient writers).[16][17][18] According to the rabbinical writers, eggs from ritually pure animals would always be prolate ("pointy") at one end and oblate ("rounded") at the other, helping to reduce uncertainty about whether consumption was permitted or not.[19][20][21]

Eggs

Jerusalem kugel made with egg noodle, caramelized sugar and black pepper

Eggs are considered pareve despite being an animal product.

The Yoreh De'ah argues that if there is blood in the egg yolk, then hatching must have begun, and therefore consumption of the egg would be forbidden.[30] Modern Orthodox Jews adhere to these requirements; however, the Ashkenazi Orthodox Jews treat an egg as nonkosher if blood is found anywhere within it.[31]^:48 Sephardi Orthodox Jews consider only blood in the yolk to be a problem, and treat eggs with blood in the albumen as legitimate food if the blood is removed before use.

Today, when battery eggs form the majority of available produce, many permit the egg with a blood spot following the removal of any actual blood; battery eggs are unlikely to be able to form a viable embryo.[32]

Gelatin

Kosher gummy bears

Gelatin is hydrolysed collagen,[33] the main protein in animal connective tissue, and therefore could potentially come from a nonkosher source, such as pig skin. Gelatin has historically been a prominent source of glue, finding uses from musical instruments to embroidery, one of the main historic emulsions used in cosmetics and in photographic film, the main coating given to medical capsule pills, and a form of food including jelly, trifle, and marshmallows; the status of gelatin in kashrut is consequently fairly controversial.

Due to the ambiguity over the source of individual items derived from gelatin, many Orthodox rabbis regard it as generally being nonkosher. However, Conservative rabbis[34] and several prominent Orthodox rabbis, including Chaim Ozer Grodzinski and Ovadia Yosef – the former Sephardic Chief Rabbi of Israel – argue that gelatin has undergone such total chemical change and processing that it should not count as meat, and therefore would be kosher.[35] Technically, gelatin is produced by separating the three strands in each collagen fiber's triple helix by boiling collagen in water. Rabbi Dr. David Sheinkopf, author of Gelatin in Jewish Law (Bloch 1982) and Issues in Jewish Dietary Laws (Ktav 1998), has published in-depth studies of the kosher uses of gelatin, as well as carmine and kitniyot.

One of the main methods of avoiding nonkosher gelatin is to substitute gelatin-like materials in its place; substances with a similar chemical behaviour include food starch from tapioca, chemically modified pectins, and carrageenan combined with certain vegetable gums – guar gum, locust bean gum, xanthan gum, gum acacia, agar, and others. Although gelatin is used for several purposes by a wide variety of manufacturers, it has started to be replaced with these substitutes in a number of products, due to the use of gelatin also being a significant concern to vegans and vegetarians.

Today manufacturers are producing gelatin from the skins of kosher fish, circumventing many of these problems.[36]

Kosher slaughter of a chicken

Of the rules appearing, in two groups, in Exodus, most do not express dietary laws, but one of the few dietary rules it does list is a ban on eating the meat from animals that have been "torn by beasts";[37] a related law appears in Deuteronomy's law code, totally prohibiting the consumption of anything that has died from natural causes, and even giving away or selling such things.[38] Some have claimed that the Book of Ezekiel implies[39] that the rules about animals that die of natural causes, or are "torn by beasts", were adhered to only by the priests,[40] and were intended only for them;[41] the implication that they did not apply to, and were not upheld by, ordinary Israelites was noticed by the classical rabbis, who declared "the prophet Elijah shall some day explain this problematic passage".[42]

Traditional Jewish thought has expressed the view that all meat must come from animals that have been slaughtered according to Jewish law. These strict guidelines require the animal be killed by a single cut across the throat to a precise depth, severing both carotid arteries, both jugular veins, both vagus nerves, the trachea and the esophagus, no higher than the epiglottis and no lower than where cilia begin inside the trachea, causing the animal to bleed to death. Orthodox Jews explain that this ensures the animal dies instantly without unnecessary suffering, but many animal rights activists view the process as cruel, claiming that the animal may not lose consciousness immediately, and activists have called for it to be banned.[43][44]

To avoid tearing, and to ensure the cut is thorough, such slaughter is usually performed by a trained individual, with a large, razor-sharp knife, which is checked before each slaughter to ensure that it has no irregularities (such as nicks and dents); if irregularities are discovered, or the cut is too shallow, the meat is deemed unkosher. Rabbis usually require the slaughterer, known within Judaism as a shochet, to also be a pious Jew of good character and an observer of the Shabbat. In smaller communities, the shochet was often the town rabbi, or a rabbi from a local synagogue, but large slaughterhouses usually employ a full-time shochet if they intend to sell kosher meat.

The Talmud, and later Jewish authorities, also prohibit the consumption of meat from animals who were slaughtered despite being in the process of dying from disease; but this is not based on concern for the health of the eater, instead being an extension of the rules banning the meat from animals torn by beasts, and animals that die from natural causes.[45][46][47] To comply with this Talmudic injunction against eating diseased animals, Orthodox Jews usually require that the corpses of freshly slaughtered animals be thoroughly inspected. There are 70 different traditional checks for irregularities and growths; for example, there are checks to ensure that the lungs have absolutely no scars, which might have been caused by an inflammation. If these checks are passed, the meat is then termed glatt (גלאַט), the Yiddish word meaning smooth.

Compromises in countries with animal cruelty laws that prohibit such practices involve stunning the animal to lessen the suffering that occurs while the animal bleeds to death. However, the use of electric shocks to daze the animal is often not accepted by some markets as producing meat that is kosher.[43]

As forbidden fats, tendons, blood vessels and the gid hanashe (sciatic nerve) must be removed, and this is more difficult in the rearquarters, often only cuts of meat from the forequarters are commonly available.

One of the main biblical food laws forbids consuming blood on account of "the life [being] in the blood". This ban and reason are listed in the Noahide Laws[51] and twice in Book of Leviticus[52][53] as well as in Deuteronomy.[54] The Priestly Code also prohibits the eating of certain types of fat (chelev) from sacrificial land animals (cattle, sheep, and goats), since the fat is the portion of the meat exclusively allocated to God (by burning it on the altar).[55]

The classical rabbis argued that, in a number of cases, only if it is impossible to remove every drop of blood, the prohibition against consuming blood was impractical, and there should be rare exceptions: they claimed that consuming the blood that remained on the inside of meat (as opposed to the blood on the surface of it, dripping from it, or housed within the veins) should be permitted and that the blood of fish and locusts could also be consumed.[56][57][58][59]

To comply with this prohibition, a number of preparation techniques became practiced within traditional Judaism. The main technique, known as meliḥah, involves the meat being soaked in water for about half an hour, which opens pores.[60] After this, the meat is placed on a slanted board or in a wicker basket, and is thickly covered with salt on each side, then left for between 20 minutes and one hour.[60] The salt covering draws blood from the meat by osmosis, and the salt must be subsequently removed from the meat (usually by trying to shake most of it off and then washing the meat twice[60]) to complete the extraction of the blood. The type of salt used in the process is known as kosher salt.

Meliḥah is not sufficient to extract blood from the liver, lungs, heart, and certain other internal organs, since they naturally contain a high density of blood, and therefore these organs are usually removed before the rest of the meat is salted. Roasting, on the other hand, discharges blood while cooking, and is the usual treatment given to these organs. It is also an acceptable method for removing blood from all meat.[60]

Rabbi in a Kosher wine shop

The classical rabbis prohibited any item of food that had been consecrated to an idol or had been used in the service of an idol.[61] Since the Talmud views all non-Jews as potential idolaters, and viewed intermarriage with apprehension, it included within this prohibition any food that has been cooked or prepared completely by non-Jews.[62][63] (Bread sold by a non-Jewish baker was not included in the prohibition.[62][63]) Similarly, a number of Jewish writers believed food prepared for Jews by non-Jewish servants would not count as prepared by potential idolaters, although this view was opposed by Jacob ben Asher.[64]

Consequently, modern Orthodox Jews generally believe wine, certain cooked foods, and sometimes even dairy products,[65][66][67] should be prepared only by Jews. The prohibition against drinking non-Jewish wine, traditionally called yayin nesekh (literally meaning "wine for offering [to a deity]"), is not absolute. Cooked wine (Hebrew: יין מבושל, yayin mevushal), meaning wine that has been heated, is regarded as drinkable on the basis that heated wine was not historically used as a religious libation; thus kosher wine will often be prepared by Jews and then pasteurised, after which it can be handled by a non-Jew. Orthodox Judaism regards wine as kosher only if prepared by a Jew.

Some Jews refer to these prohibited foods as akum, an acronym of Ovde Kokhavim U Mazzaloth (עובדי כוכבים ומזלות), meaning "worshippers of stars and planets (or Zodiac)". Akum is thus a reference to activities that these Jews view as idolatry, and in many significant works of post-classical Jewish literature, such as the Shulchan Aruch, it has been applied to Christians in particular. However, among the classical rabbis, there were a number who refused to treat Christians as idolaters, and consequently regarded food that had been manufactured by them as being kosher; this detail has been noted and upheld by a number of religious authorities in Conservative Judaism, such as Rabbi Israel Silverman, and Rabbi Elliot N. Dorff.

Conservative Judaism is more lenient; in the 1960s, Rabbi Silverman issued a responsum, officially approved by the Committee on Jewish Law and Standards, in which he argued that wine manufactured by an automated process was not "manufactured by gentiles", and therefore would be kosher. A later responsum of Conservative Judaism was issued by Rabbi Dorff, who argued, based on precedents in 15th-19th century responsa, that many foods, such as wheat and oil products, which had once been forbidden when produced by non-Jews were eventually declared kosher. On this basis he concluded wine and grape products produced by non-Jews would be permissible.

For obvious reasons, the Talmud adds to the biblical regulations a prohibition against consuming poisoned animals.[68] Similarly, Yoreh De'ah prohibits the drinking of water, if the water had been left overnight and uncovered in an area where there might be serpents, on the basis that a serpent might have left its venom in the water.[69] In a place where there is no suspicion of snakes, this prohibition does not apply (tosafos, beitzah 6a).

Three times the Torah specifically forbids "seething" a young goat "in its mother's milk" (Exodus 23:19, Exodus 34:26, and Deuteronomy 14:21). The Talmud interprets this as a general prohibition against cooking meat and dairy products together, and against eating or deriving any benefit from such a mixture. To help prevent accidental violation of these rules, the modern standard Orthodox practice is to classify food into either being meat, dairy, or neither; this third category is more usually referred to as parev from the Yiddish word parev (פארעוו) (also spelled parve and pareve) meaning "neutral". As the biblical prohibition uses the word "Gedi" and not "Gedi Izim", the flesh of all "Behemoth" (domestic mammals) is categorised as "meat", while that of fish and bugs is considered parve; however, rather than being considered parve, the flesh of birds and "chayot" (like deer) has been regarded by halakha (Jewish law) as meat for over 2000 years, by Rabbinic decree.

One of the major dietary laws that observant Jews keep of Kashruth is that dairy and meat may not be eaten at the same meal. Though it is mentioned many times in the Hebrew Bible, Rashi held that it was connected to two major ethical laws in the Jewish heritage from the original Five Books of Moses, which are, first, to respect the mother animal: Exodus 23:19 "You shall not boil a kid in its mother's milk"; and, secondly, Deuteronomy 22:6 "If you come across a bird's nest beside the road, either in a tree or on the ground, and the mother is sitting on the young or on the eggs, do not take the mother with the young." Some held these relate to the "hurt to living" (tzaar baalei chaim) statute cited throughout Jewish law, against hurting any living thing, the Mishnah Avoth 1:12, "Be a disciple of Aaron... and love all of God's animals" (chaim, living); also, "His compassion is over all of His creatures" (Psalms 145:9) and again the term is chaim, living things.

The Talmud and Yoreh Deah suggest that eating meat and fish together may cause tzaraath.[70][71] Strictly Orthodox Jews thus avoid combining the two,[72][73] while Conservative Jews may or may not.[73]

The laws of kashrut can be broken for pikuach nefesh (preservation of human life). For example, a patient is allowed to eat non-kosher food if it is essential for recovery,[74] or where the person would otherwise starve.[75][76]

Each year 5,000 food industry vendors, kosher certification agencies, journalists and other professionals gather in New York City to sample kosher fare from 300 event attendees. Among the offerings at the 2018 Kosherfest were plantain croutons from Ecuador. The gluten free croutons won the Kosherfest award for best new snack. There were breaded dessert ravioli stuffed with sweet ricotta and chocolate chips, pareve and vegan "ice cream" cake made from cherry and passion fruit sorbet, butter substitute made from coconut oil, and a gluten free variation of Syrian sambusak dumplings.[77]

• Hasia R. Diner and Simone Cinotto (eds.), Global Jewish Foodways: A History. Lincoln, NE: University of Nebraska Press, 2018.

• Religious Rules: Laws of Judaism Concerning Food
• Aish.com: ABCs of Kosher
• Chabad.org: Kosher - Eating Jewishly
• Kashrut.com: The Premier Kosher Information Source on the Internet
• Orthodox Union Kosher certification
• OK Kosher Certification
• Yeshiva.co: What is Kosher?